Monday, October 26, 2015

Season 8 stage 3 rounds 21-25

After 25 rounds (5RR) the crosstable is:

Gull continued losing points and it is now 2.5 points behind Stockfish in second place. After losing to both Komodo and Stockfish it is now difficult to imagine Gull making a comeback and reaching the final.

Komodo-Hannibal got into a knight for 3 pawns imbalance.The game reached a RRN vs RR ending with Komodo losing all its pawns. I don't know what the theory is for this ending, but Hannibal managed to hold a draw even with no tablebase help.

Stockfish managed to beat Gull in a Rook ending, turning a passed pawn on one side to a winning advantage on the other. Stockfish saw the win long before Gull caught on, having no tablebase assistance. In the next Stockfish game, black against Hannibal, Stockfish fought hard for a two pawn advantage. Unfortunately the game reached a opposite color bishop ending and two pawns were not enough, Hannibal holding another draw.

The RR ended with the Komodo-Stockfish game. On move 28 of the game things started to get exciting when Komodo's eval jumped suddenly and Stockfish was under pressure, a rare occurance in this season so far. Stockfish defended well, first exchanging a rook for a bishop and trading queens, and then getting the exchange back. Komodo had an extra pawn but the opposite bishops ending was a sure draw. Another feature of this game was that a little after the excitement started the website went offline for a long time, and the viewers were left in the dark as to how the game was unfolding. The web host apparently was undergoing maintainance, could it be something to do with the end of the daylight saving period?? Hopefully this will not happen again, it is very annoying to have no access to the live games.

Here Protector decided to go after the queen side pawns with its queen. In the process the queen walks into a trap:

The white queen can't move! On the other hand the black queen is neccesary for the trap, so altogether the position is still balanced with the queens out of the way. A few moves later Komodo finds an unexpected maneuver to create a decisive advantage: the king goes on a walk:

It walked from g8 to c3 with no pawns or pieces to stop it. Komodo sacrificed a pawn in the process, but with the king as an additional piece behind the white lines it has more than enough compensation. When Komodo releases the white queen the game soon enters a queen ending, but black has a two pawn advantage, enough for a win.